#include <iostream>
#include <cstdlib>
using namespace std;

int main()
{
    int offset = static_cast<int>('a' - 'A');
//    char mya = "a", myA = "A";
//    cout << "a's ASCII: " << atoi('a') << ", A's ASCII is " << atoi('A')  << ", offset is: " << offset << endl;
    cout << "Please enter an Upper case letter: ";
    char myChar;
    cin >> myChar;
    cout << "The lower case letter of this letter is: " << static_cast<char>(myChar + offset) << endl;

    return 0;
}
